scholarly journals Early Archean origin of heterodimeric Photosystem I

2017 ◽  
Author(s):  
Tanai Cardona
Keyword(s):  
Gene Duplication ◽  
Photosystem I ◽  
Water Oxidation ◽  
Duplication Event ◽  
Oxygenic Photosynthesis ◽  
Recent Common Ancestor ◽  
Type I ◽  
Reaction Centre ◽  
Gene Duplication Event ◽  
Most Recent Common Ancestor

AbstractWhen and how oxygenic photosynthesis originated remains controversial. Wide uncertainties exist for the earliest detection of biogenic oxygen in the geochemical record or the origin of water oxidation in ancestral lineages of the phylum Cyanobacteria. A unique trait of oxygenic photosynthesis is that the process uses a Type I reaction centre with a heterodimeric core, also known as Photosystem I, made of two distinct but homologous subunits, PsaA and PsaB. In contrast, all other known Type I reaction centres in anoxygenic phototrophs have a homodimeric core. A compelling hypothesis for the evolution of a heterodimeric Type I reaction centre is that the gene duplication that allowed the divergence of PsaA and PsaB was an adaptation to incorporate photoprotective mechanisms against the formation of reactive oxygen species, therefore occurring after the origin of water oxidation to oxygen. Here I show, using sequence comparisons and Bayesian relaxed molecular clocks that this gene duplication event may have occurred in the early Archean more than 3.4 billion years ago, long before the most recent common ancestor of crown group Cyanobacteria and the Great Oxidation Event. If the origin of water oxidation predated this gene duplication event, then that would place primordial forms of oxygenic photosynthesis at a very early stage in the evolutionary history of life.

scholarly journals Early Archean origin of Photosystem II

2017 ◽  
Author(s):  
Tanai Cardona ◽  
Patricia Sánchez-Baracaldo ◽  
A. William Rutherford ◽  
Anthony W. D. Larkum
Keyword(s):  
Photosystem Ii ◽  
Reaction Center ◽  
Water Oxidation ◽  
Photochemical Reaction ◽  
Early Stage ◽  
Oxygenic Photosynthesis ◽  
Recent Common Ancestor ◽  
Molecular Clocks ◽  
Most Recent Common Ancestor ◽  
History Of

AbstractPhotosystem II is a photochemical reaction center that catalyzes the light-driven oxidation of water to molecular oxygen. Water oxidation is the distinctive photochemical reaction that permitted the evolution of oxygenic photosynthesis and the eventual rise of Eukaryotes. At what point during the history of life an ancestral photosystem evolved the capacity to oxidize water still remains unknown. Here we study the evolution of the core reaction center proteins of Photosystem II using sequence and structural comparisons in combination with Bayesian relaxed molecular clocks. Our results indicate that a homodimeric photosystem with sufficient oxidizing power to split water had already appeared in the early Archean about a billion years before the most recent common ancestor of all described Cyanobacteria capable of oxygenic photosynthesis, and well before the diversification of some of the known groups of anoxygenic photosynthetic bacteria. Based on a structural and functional rationale we hypothesize that this early Archean photosystem was capable of water oxidation and had already evolved some level of protection against the formation of reactive oxygen species, which would place primordial forms of oxygenic photosynthesis at a very early stage in the evolutionary history of life.

A new aminopeptidase from diamondback moth provides evidence for a gene duplication event in Lepidoptera

1999 ◽  
Vol 8 (2) ◽  
pp. 171-177 ◽  
Author(s):  
W. X. Z. Chang ◽  
L. J. Gahan ◽  
B. E. Tabashnik ◽  
D. G. Heckel
Keyword(s):  
Gene Duplication ◽  
Diamondback Moth ◽  
Duplication Event ◽  
Gene Duplication Event

scholarly journals Structure and Characterization of Crimean-Congo Hemorrhagic Fever Virus GP38

2020 ◽  
Vol 94 (8) ◽  
Author(s):  
Akaash K. Mishra ◽  
Crystal L. Moyer ◽  
Dafna M. Abelson ◽  
Daniel J. Deer ◽  
Kamel El Omari ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Gene Duplication ◽  
Mouse Model ◽  
Hemorrhagic Fever ◽  
Duplication Event ◽  
Fever Virus ◽  
Gene Duplication Event ◽  
Protective Antibody ◽  
Crimean Congo Hemorrhagic Fever ◽  
Hemorrhagic Fever Virus

ABSTRACT Crimean-Congo hemorrhagic fever virus (CCHFV) is the causative agent of the most widespread tick-borne viral infection in humans. CCHFV encodes a secreted glycoprotein (GP38) of unknown function that is the target of a protective antibody. Here, we present the crystal structure of GP38 at a resolution of 2.5 Å, which revealed a novel fold primarily consisting of a 3-helix bundle and a β-sandwich. Sequence alignment and homology modeling showed distant homology between GP38 and the ectodomain of Gn (a structural glycoprotein in CCHFV), suggestive of a gene duplication event. Analysis of convalescent-phase sera showed high titers of GP38 antibodies indicating immunogenicity in humans during natural CCHFV infection. The only protective antibody for CCHFV in an adult mouse model reported to date, 13G8, bound GP38 with subnanomolar affinity and protected against heterologous CCHFV challenge in a STAT1-knockout mouse model. Our data strongly suggest that GP38 should be evaluated as a vaccine antigen and that its structure provides a foundation to investigate functions of this protein in the viral life cycle. IMPORTANCE Crimean-Congo hemorrhagic fever virus (CCHFV) is a priority pathogen that poses a high risk to public health. Due to the high morbidity and mortality rates associated with CCHFV infection, there is an urgent need to develop medical countermeasures for disease prevention and treatment. CCHFV GP38, a secreted glycoprotein of unknown function unique to the Nairoviridae family, was recently shown to be the target of a protective antibody against CCHFV. Here, we present the crystal structure of GP38, which revealed a novel fold with distant homology to another CCHFV glycoprotein that is suggestive of a gene duplication event. We also demonstrate that antibody 13G8 protects STAT1-knockout mice against heterologous CCHFV challenge using a clinical isolate from regions where CCHFV is endemic. Collectively, these data advance our understanding of GP38 structure and antigenicity and should facilitate future studies investigating its function.

scholarly journals Phylogenetic analysis of eukaryotic NEET proteins uncovers a link between a key gene duplication event and the evolution of vertebrates

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Madhuri A. Inupakutika ◽  
Soham Sengupta ◽  
Rachel Nechushtai ◽  
Patricia A. Jennings ◽  
Jose’ N. Onuchic ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Duplication ◽  
Duplication Event ◽  
Gene Duplication Event

scholarly journals Structure of the far-red light utilizing photosystem I of Acaryochloris

2020 ◽  
Author(s):  
Tasuku Hamaguchi ◽  
Keisuke Kawakami ◽  
Kyoko Shinzawa-Itoh ◽  
Natsuko Inoue-Kashino ◽  
Shigeru Itoh ◽  
...  
Keyword(s):  
Photosystem I ◽  
Red Light ◽  
Primary Electron ◽  
Oxygenic Photosynthesis ◽  
Energy Yield ◽  
Type I ◽  
Cryo Electron Microscopy ◽  
Primary Electron Acceptor ◽  
Acaryochloris Marina ◽  
Electron Carriers

Abstract Acaryochloris marina is a cyanobacterium that can, uniquely, use far-red light for oxygenic photosynthesis. Here, we report the structure of the photosystem I reaction center of A. marina determined by cryo-electron microscopy at 2.5 Å resolution. The structure reveals a unique arrangement of electron carriers and light harvesting pigments. The primary electron donor P740 is a dimer of chlorophyll d/d′ and the primary electron acceptor pheophytin a, a metal-less chlorin different from the chlorophyll a common to all other oxygenic type I reaction centers. The architecture of the 11 subunits and identity of key components help explain how the low energy yield from far-red light is efficiently utilized for driving oxygenic photosynthesis.

scholarly journals Photosynthesis: basics, history and modelling

2019 ◽  
Vol 126 (4) ◽  
pp. 511-537 ◽  
Author(s):  
Alexandrina Stirbet ◽  
Dušan Lazár ◽  
Ya Guo ◽  
Govindjee Govindjee
Keyword(s):  
Chlorophyll A ◽  
Water Oxidation ◽  
Carbon Fixation ◽  
Agricultural Land ◽  
Atp Synthesis ◽  
Oxygenic Photosynthesis ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Exciting Light ◽  
Reaction Centre

Abstract Background With limited agricultural land and increasing human population, it is essential to enhance overall photosynthesis and thus productivity. Oxygenic photosynthesis begins with light absorption, followed by excitation energy transfer to the reaction centres, primary photochemistry, electron and proton transport, NADPH and ATP synthesis, and then CO2 fixation (Calvin–Benson cycle, as well as Hatch–Slack cycle). Here we cover some of the discoveries related to this process, such as the existence of two light reactions and two photosystems connected by an electron transport ‘chain’ (the Z-scheme), chemiosmotic hypothesis for ATP synthesis, water oxidation clock for oxygen evolution, steps for carbon fixation, and finally the diverse mechanisms of regulatory processes, such as ‘state transitions’ and ‘non-photochemical quenching’ of the excited state of chlorophyll a. Scope In this review, we emphasize that mathematical modelling is a highly valuable tool in understanding and making predictions regarding photosynthesis. Different mathematical models have been used to examine current theories on diverse photosynthetic processes; these have been validated through simulation(s) of available experimental data, such as chlorophyll a fluorescence induction, measured with fluorometers using continuous (or modulated) exciting light, and absorbance changes at 820 nm (ΔA820) related to redox changes in P700, the reaction centre of photosystem I. Conclusions We highlight here the important role of modelling in deciphering and untangling complex photosynthesis processes taking place simultaneously, as well as in predicting possible ways to obtain higher biomass and productivity in plants, algae and cyanobacteria.

scholarly journals Evolution of the Heme Peroxidases of Culicidae (Diptera)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Austin L. Hughes
Keyword(s):  
Amino Acid ◽  
Gene Duplication ◽  
Common Ancestor ◽  
Expression Patterns ◽  
Amino Acid Level ◽  
Recent Common Ancestor ◽  
Amino Acid Sequence Level ◽  
Most Recent Common Ancestor ◽  
High Level ◽  
Heme Peroxidases

Phylogenetic analysis of heme peroxidases (HPXs) of Culicidae and other insects revealed six highly conserved ancient HPX lineages, each of which originated by gene duplication prior to the most recent common ancestor (MRCA) of Hemimetabola and Holmetabola. In addition, culicid HPX7 and HPX12 arose by gene duplication after the MRCA of Culicidae and Drosophilidae, while HPX2 orthologs were not found in any other order analyzed except Diptera. Within Diptera, HPX2, HPX7, and HPX12 were relatively poorly conserved at the amino acid level in comparison to the six ancient lineages. The genome ofAnopheles gambiaeincluded genes ecoding five proteins (HPX10, HPX11, HPX13, HXP14, and HPX15) without ortholgs in other genomes analyzed. Overall, gene expression patterns did not seem to reflect phylogenetic relationships, but genes that evolved rapidly at the amino acid sequence level tended to have divergent expression patterns as well. The uniquely high level of duplication of HPXs inA. gambiaemay have played a role in coevolution with malaria parasites.

scholarly journals Sequences encoding two trypsin inhibitors occur in strikingly similar genomic environments

1986 ◽  
Vol 233 (2) ◽  
pp. 443-450 ◽  
Author(s):  
I B Kingston ◽  
S Anderson
Keyword(s):  
Gene Duplication ◽  
Trypsin Inhibitor ◽  
Bovine Genome ◽  
Duplication Event ◽  
The Other ◽  
Bovine Pancreatic Trypsin Inhibitor ◽  
Gene Duplication Event ◽  
Coding Region ◽  
Pancreatic Trypsin Inhibitor ◽  
Putative Intron

The nucleotide sequences of two approx. 4 kilobase pair segments of the bovine genome are presented. One segment contains a coding region for bovine pancreatic trypsin inhibitor (BPTI) and the other segment contains a coding region for a BPTI homologue. The two 4 kilobase pair sequences are strikingly similar over approx. 3.4 kilobase pairs of their sequence, including putative intron sequences, suggesting that they have evolved from a gene duplication event.

scholarly journals Mutually Exclusive Expression of Closely Related Odorant-Binding Proteins 9A and 9B in the Antenna of the Red Flour Beetle Tribolium castaneum

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1502
Author(s):  
Alice Montino ◽  
Karthi Balakrishnan ◽  
Stefan Dippel ◽  
Björn Trebels ◽  
Piotr Neumann ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Tribolium Castaneum ◽  
Gene Pair ◽  
Binding Proteins ◽  
Duplication Event ◽  
Food Sources ◽  
Gene Duplication Event ◽  
Odorant Binding Proteins ◽  
Receptor Complexes ◽  
Odorant Binding

Olfaction is crucial for insects to find food sources, mates, and oviposition sites. One of the initial steps in olfaction is facilitated by odorant-binding proteins (OBPs) that translocate hydrophobic odorants through the aqueous olfactory sensilla lymph to the odorant receptor complexes embedded in the dendritic membrane of olfactory sensory neurons. The Tribolium castaneum (Coleoptera, Tenebrionidae) OBPs encoded by the gene pair TcasOBP9A and TcasOBP9B represent the closest homologs to the well-studied Drosophila melanogaster OBP Lush (DmelOBP76a), which mediates pheromone reception. By an electroantennographic analysis, we can show that these two OBPs are not pheromone-specific but rather enhance the detection of a broad spectrum of organic volatiles. Both OBPs are expressed in the antenna but in a mutually exclusive pattern, despite their homology and gene pair character by chromosomal location. A phylogenetic analysis indicates that this gene pair arose at the base of the Cucujiformia, which dates the gene duplication event to about 200 Mio years ago. Therefore, this gene pair is not the result of a recent gene duplication event and the high sequence conservation in spite of their expression in different sensilla is potentially the result of a common function as co-OBPs.

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